Electric heater.



W. D. HUI-'I'.

ELECTRIC HEATER.

APPLICATION FILED MAY 27, I9I5.

1,169,262. Patented @11.251916 v'WILLIAIllllI DANIEL HUFF, OF LA FAYETTE, LOUISIANA.

ELECTRIC Ennemi.L

Application leqiay 27, 1915. E Serial No. 30,784.

To all lwhom it may concern: l

Be it known that I, WILLIAM DANmL HUFr, a citizen of the United States, residing at La Fayette, in the parish of Lafayette and State of Louisiana, have inventedV certain new and useful' Improvements in Electric Heaters; and I do hereby declare the following to be a ful-l, clear, and exact description of the invention, such as will enable others skilled in the art to which it' appertains to make and use the same# My present invention relates to improve- Y ments in electric heaters, and is especially intended to apply to electric heaters adapted for use submerged in liquids, such as crude oil, water, or the like.

4My invention is especially intended to relate to electric heaters adapted for use in oil or sulfur wells, in which it is desired` to heat the liquid contained inthe well. This heating is frequently desired for the upurpose of generating pressure in the well,

either for pumping the contents thereof out of the Well, or for forcing the heated liquid in the well back into the strata of earth for the purpose of cleaning the same and increasing the flow of the well, as fully described in my applications entitled Operating oil wells, Serial No. 19607, led A pril 6, 1915; Operating sulfur wells, Serial No.

22874, led April 20, 1915; and Cleaning oilv wells, Serial No. 24463, led April 28, 1915.

According to my invention I intend to use the heaters either singly or in.. groups, as may be desired, and the same are preferably applied to the central pipe or delivery tube mounted in. wellsof the character described in my applications aforesaid. I do not intend to limit my invention, however, to use in Wells alone, but it may be used in a great variety of ways. s

Reference is had to the accompanying drawings, in which I haveA shown `one embodiment of the invention as applied to use in wells, and in which Figure 1 shows a central vertical section through the well casing, the heaters-and inner pipe .of the well being shown in elevation, and parts being'broken aWay;-Fi'g. 2

is an enlarged view of the heater as'mounted in the well, parts being broken away; and- Fig.` 3 shows a section along the line 3-3 of Fig. 2, and looking down. f

A represents the outer casing of the Well` which is perforated at the bottom, as at a,

or provided with a suitable screen well4 known in the art. The top of the well is closed by a cap B, with suitable packing b and projecting down into the center of the we ll is a delivery pipe C, for delivering the fluid contents of the well, which pipe is controlled by the valve C. v

D represents a pressure pipe having a safety valve rol, a pressure gage d', and a valveI D to open or close said pipe whenv desired.

specification of Letters Patent.4 A Patented Jan, 25, 1916;;-

Electricity issupplied'y from any suitable source, as from the electric generator E, and passes through the switchboard F and the cabler Gr to the heaters H and H, which are slipped over the inner pipe C and suspended in the well, asshown in Fig. 1. These heaters are arranged to be used singly or in groups, and whenused in groups are connelctedA together in any suitable way, as by' means of the straps h and the bolts h.

` The heaters are constructed as `shown in ,F1gs. 2 and 3, in which there are twol annular heads 1 and la, preferably in thel form of hollow cylinders closed at the inner ends 2 andy open at the outer ends, and provided with an' inner cylindrical wall 8. These two heads -1 and 1a are reversely disposed, and the diaphragms 2 are connected together by the tubes 4 which are of copper, or other suitable metal, secured tight in said daphragms 2, as by swaging, brazing, or otherwise. Rove through these tubes 4 are the heating wires 5, which wires are spaced'from lsaidtubeby mica, glass beads, or other suitable insulating material, shown at 6 in Fig.

2, and the leading-in wires 7 to each heater vpass through insulated plugs 8 in the cap 9 and are connectedto the armored cable G. The cap 9 is in the form of a flanged ring,

and is made to close the top of the annular .heater thus formed is air and water tight,

and its .eiiciency is increased by pumping the air out of the two heads 1 and 1a and of the connecting tubes 4 by an air pump 105 connected to the cock 10, and then filling bubbles of the vacuum in the heater with nitrogen gas. The vacuum is a poor conductor of heat, but the nitrogen gas serves as a conductor by the convection currents generated therein; and moreover being an inert gas it prevents the inclosed parts from becoming oxidized, as would be the case if exposed to the imprisoned air when highly heated, as would ordinarily occur in heaters of this kind.

It will'be evident that if the gas beforced in under pressure, and a heater be suband other parts contained on the insideof the heater are protected from oxidation, which is a very serious diiiculty with .elec- Itric heaters where these parts are exposed to the oxygen of the atmosphere. Moreover, the heating wires may be heated to a higher temperature without injury. As is well known, the resistance to the electric current increases with the temperature, and the economica-l eliciency of an electric heater increases with the temperature of the heating wires.

The heater may be supported in the inner pipe C in any convenient way, as by the wedge K passingl through a slot in the inner pipe C, and held in place by the "cotter pin k.

The electric current may be carried both ways, through the cable G, but it will ordinarily be 'preferable to have the current supplied through the leading-in wire from said cable, and the other wire grounded as 'by connection with the inner pipe C, or the well casing A, or both.

While I have shown my inventionas applied to use in wells, it will be obvious that it may be applied in various other relations,r`

whether submerged or. mounted in the air, or wherever located, and I do not mean to limit my invention to any particular use.

' It will be obvious that various'modiications might be made in the herein described apparatus, and in the construction,combi nation and arrangement of parts which could be used without departing 1from the spirit of my invention.

Having thus described vmy invention, what I claim and desire to secure by- Letters Patent of the United States is 1. An electric heater comprising two hollow annular heads adapted to be placed around a central pipe, tubes connecting said heads, the joints in said heads and tubes being substantially air-tight, heating wires rovethroughsaid tubes, and means for conveying an electric'icurrent to said wires, substantially as described.

2. An electric heater comprising two hollow annular heads, tubes connecting said heads, the joints in said heads and tubes being substantially air-tight, heating wires rove through said tubes, a cock openin into one of said heads and adapted to ex iaust lthe air from the interior of said heads and said tubes, and to charge same with an inert gas, and means for conveying an electric current to said wires, substantially as described.

3. An electric heater comprising two hollow annular heads adapted to be placed around a central. pipe, tubes connecting said heads, the joints in'said heads and tubes being substantially air-tight, heating wires rove'through said tubes, and means for conveying an electric current to said wires,

with nitrogen gas fillin the hollow portions of-said heads and sai tubes, substantially as and for the purposes described.

4. An electric heater comprising two hollow annular heads, tubes connecting said heads, the jointsin said heads and tubes being substantially air-tight, heating wires rove through said tubes, a cock opening in to one of said heads and adapted to exhaust the air from the interior of said heads and said tubes, and to charge same with an inert gas, and means for conveying an electric current to said wires, with nitrogen gas filling the hollow portions of said heads and said tubes, substantially as and for the purposes described.

5. An electric heater comprising two hollow heads, tubes connecting said heads, the joints in said heads and tubes being substantially air-tight, heating wires rove through said tubes and spaced therefrom by insulating materialpa cock opening into one of said heads and adaptedto exhaust the air from the interior of said heads and said tubes, and to charge same with an inert gas, and means for conveying an electric current to said wires, substantially as described. j

'6. An electric heater comprisin two hollow heads, tubes connecting said eads, the joints in said heads and tubes being substantially air-tight, heating wires rove through said tubes and spaced therefrom by insulating material, a cock opening into one of said heads and adapted to exhaust the air from the interior of said heads and said tubes, and to charge same with an inert gas, and means for conveying an electric current to said wires, with nitrogen gas'lling the hollow portions of said heads and said tubes, substantially as and for the purposes described.

7. An electric heater comprisin two hollow heads, tubes connecting said l(heads, the

to said wires, with an inert gas filling the hollow portions of said 4heads and said ltubes,substantially as and for the purposes described.

In testimony whereof, I 4aiix my signature.

WILLIAM DANIEL HFF. 

